This invention relates generally to Radio Frequency Identification systems, particularly to a system and method for identification and tracking of aircraft components.
Controlling and verifying configurations of aircraft, such as, for example, commercial aircraft and military aircraft, is very labor intensive. Typically, thousands of serial numbered parts have to be tracked by hand using paper forms, resulting in inevitable errors in determining and recording of the exact parts that are on an airplane. The task of tracking aircraft parts on a given aircraft becomes even more complicated as time goes on, for example, due to maintenance procedures such as “D” checks that are conducted periodically during the life of an aircraft, during which many parts may be replaced, and/or repaired. Because of the sheer volume of data that must be entered into the records maintained for each aircraft, errors are bound to occur during data entry of information in relation to the condition and/or history of one or more aircraft components.
As a result, tracking maintenance history on aircraft parts is currently a fairly complex operation. There is typically no on-site method for a mechanic to determine the maintenance history of a given part.
Radio Frequency Identification (“RFID”) is an extremely powerful and cost effective technology that allows a wide range of objects to be identified, tracked and managed. RFID technology is based on the use of small radio tags or transponders and readers/encoders for connection to an information system. These RFID tags, which contain a unique code together with other additional information that may be specified by the user, can be read by the reader/encoder from a distance without contact or line-of-sight. Tagging and tracking of products and devices utilizing radio frequency identification is widely used in manufacturing and packaging processes, but has not yet been used to label individual component parts of large complex machines.
A basic RFID system consists of three components: an antenna or coil, a transceiver (with decoder), and a transponder (RF tag) electronically programmed with unique information. Often the antenna is packaged with the transceiver and decoder to become a reader or interrogator, which can be configured either as a handheld or a fixed-mount device. The reader emits radio or magnetic waves in ranges of anywhere from one inch to 100 feet or more, depending upon its power output and the radio frequency used. When a RFID tag is within the electromagnetic zone of a transceiver, it detects the reader's activation signal. The electromagnetic field activates the RFID tag (transponder) attached to and associated with an object. In response, the RFID tag transmits an identifier code to the reader to indicate the presence of the object to which it is attached. Because of the characteristics of electromagnetic energy, there does not have to be a direct line of sight between the reader and the RFID tag. The reader, which acts as a transceiver, decodes the data encoded in the tag's integrated circuit (typically a silicon chip) and the data is passed to a host computer for processing. The reader/encoder may also write data to the RFID tag.
RFID tags are available in a wide variety of shapes and sizes. Tags can be configured as small as possible. In some instances, the RFID tag may be as small as a pencil lead in diameter and one-half inch in length. In an aircraft, it would be desired to have the RFID tags as small as possible in order to keep the payload (e.g., weight) as low as possible, thereby allowing for maximum fuel efficiency.
RFID tags are categorized as either active or passive. Active RFID tags are powered by an internal battery and are typically read/write, i.e., tag data can be rewritten and/or modified. An active tag's memory size varies according to application requirements; some systems operate with up to 1 MB of memory. In a typical read/write RFID work-in-process system, a tag might give a machine a set of instructions, and the machine would then report its performance to the tag. This encoded data would then become part of the tagged part's history. The battery-supplied power of an active tag generally gives it a longer read range. The trade off is greater size, greater cost, and an operational life limited to about 10 years depending on operating temperatures and battery type.
Passive RFID tags operate without an internal power source and obtain operating power from the transmissions generated by the reader. Consequently, passive tags are much lighter than active tags, less expensive, and offer a virtually unlimited operational lifetime. The trade off is that they have shorter read ranges than active tags and require a higher-powered reader. Read-only tags are typically passive and are programmed with a unique set of data (usually 32 to 128 bits) that cannot be modified. Read/write tags may also be passive. They are programmed with a unique set of data and such data may be modified and updated at desired intervals.
The significant advantage of all types of RFID systems is the non-contact, non-line-of-sight nature of the technology. Tags can be read through a variety of substances, including metal, where barcodes or other, traditional optically read technologies would be useless. RFID tags can also be read in challenging circumstances at remarkable speeds, in most cases responding in less than 100 milliseconds.
Conventional procedures for identification of in-service and on-board aircraft components during aircraft maintenance operations are through visual identification by way of reading labels and or part numbers affixed to the components. The problem with such conventional procedures is that reading labels and or part numbers is a time consuming and difficult process in adverse weather conditions, darkness, and crowded or cramped spaces. Maintenance technicians spend countless hours “visually” identifying aircraft components. As part of the identification process, they often use awkward tools such as flashlights and mirrors and in many instances remove access panels and other components, sometimes unnecessarily, to gain visual access to aircraft components for visual identification. This results in possible errors and long delays in flight schedules as well as inadvertent part removal, physical injury, and aircraft damage.
Personal injury, aircraft damage, lost parts, and extensive unnecessary hours of expended labor are all a result of the current method of visually identifying aircraft components. Airline operations count on efficient line and base maintenance practices, which in today's fiercely competitive maintenance environment, requires every possible advantage to become and/or remain successful. Darkness, where and during when most line maintenance occurs, greatly reduces a technician's ability to quickly locate a component. Extreme cold or hot temperatures affect a technician's physical ability. Rain, sleet, snow, wind and other environmental impacts affect a technician's physical ability. The pressures of fast turnaround and a high paced aircraft operational environment affect a technician physically and mentally. All of the aforementioned issues can impact the safety of the traveling public as well as the technician. Accordingly, there is a need for a system and method that allows for a more efficient identification of aircraft components in adverse weather conditions, darkness, and crowded or cramped spaces. There is also a need for a method of identifying aircraft component parts that are not in a maintenance technician's direct line of sight, whereby such components may be identified without removal of access panels and other components. There is further a need for a system that provides for the local storage of maintenance information, so that maintenance records are always with the components and the records are readily available to all technicians and mechanics in the field.